Earth and the Moon

The third planet from the Sun is the planet Earth. It is the largest terrestrial planet in the solar system. Earth has only one satellite, which is the Moon.

Earth rotates around the Sun on an axis of rotation that is tilted by 23.5 degrees to the axis of its orbit, causing Earth to have seasons. The tilt makes days longer and the midday Sun higher in the sky in the summer than winter. It is a common misconception that seasons are caused by the varying distance from Earth to the Sun; however the truth is that the distance only varies slightly.

How was the Moon formed?

A leading hypothesis suggests that the Moon was formed when an object about the side of Mars collided with the young Earth. The debris was eventually pulled together by Earth’s gravity to form the Moon.

What will be the temperature of the future Earth when the Sun becomes a white dwarf?

In approximately 4.5 billion years from now, the Sun will become a white dwarf and this change will have a drastic effect on the Earth’s temperature. The current temperature of the Earth is about 285 K (12 °C) but it will drop to 90 K (-183 °C) when the Sun becomes a white dwarf. Unfortunately, this is the temperature at which oxygen becomes liquid. Oxygen will rain down on Earth’s surface and the atmosphere will only be composed of nitrogen. There will still be air to breathe but it will not contain oxygen, which most living things require.

News

This website accompanies the scale model of the solar system which starts outside Room 128 in the Petrie Science and Engineering building on the Keele Campus of York University (click for directions) and spirals up to the York University Observatory on the third floor of Petrie.

Credits

Website constructed by YSSSTP student Osato Idemudia in 2010, revamped by York Observatory student intern Visal Sok in 2013, and updated by high school student Shruthi Sailesh in 2015, under the supervision of Prof. Patrick Hall and Dr. Ali Rafiee.